Abstract： Objective To explore the effect of human urinary kallikrein on the expression of VEGF in focal cerebral ischemia-reperfusion rats. Methods Fifty-six male SD rats were randomly divided into sham operated group (n=8), saline group (n=24) and human urinary kallikrein group (n=24).The latter 2 groups were made into middle cerebral artery occlusion (MCAO) models, and subdivided into 5 subgroups according to the five time points of 6, 12, 24, 72 h, and 7 d after ischemia-reperfusion.We used the methods of nerve function scales, TTC staining, infarct size estimation, detection with light microscope to evaluate the MCAO rat models at different time points, and analyzed the changes of the expression of VEGF in the center and the periphery of infarcts at different time points by immunohistochemical methods. Results The degrees of neurological impairment in the rats of human urinary kallikrein group were lighter than those of saline group (P＜0.05). The average infarct size of rats at 24 h was (53 261.96±7 326.75) μm3 in human urinary kallikrein group, (92 715.84±13 755.44) μm3 in saline group, and the difference between the 2 groups was significant (P＜0.05). The expression of VEGF in the rats of human urinary kallikrein group was higher than that of saline group at different time points (P＜0.05). Conclusions Human urinary kallikrein has neuroprotective effect after ischemia reperfusion injury, and can promote the levels of VEGF expression.